This invention relates to surgical fasteners, and more particularly to a two-part fastener for facilitating the approximation of the edges of a wound or incision in body tissue, particularly fascia tissue.
Surgical stapling devices allow a surgeon to fasten body tissue by applying surgical fasteners, such as staples or clips. The fasteners may be applied singly in succession or a number may be applied simultaneously. Surgical fasteners are often made of metals such as tantalum or stainless steel, which are inert. Fasteners of magnesium, which fasteners are gradually absorbed by the body, are also known.
Non-metallic fasteners are also known and in some cases may have certain advantages over metal fasteners. For example, metal fasteners in the body may scatter X-rays and may therefore degrade the quality of radiographs.
However, metal fasteners also have certain advantages over non-metallic fasteners. They can be bent or crimped and will hold their new shape in or around tissue. In contrast, objects of non-metallic resinous materials are usually too resilient (i.e., elastic) to hold deformed shapes (assuming plastic flow does not occur). (As used herein, the term "resinous materials" means non-metallic materials, such as natural or synthetic polymers and resins, including protein-based materials, which are relatively flexible and elastic, and which may or may not be absorbable in the body.)
To circumvent this characteristic of resinous materials, surgical fasteners of these materials may be made in two parts: a fastener member and a retainer member. The prong or prongs of the fastener member are driven through one side of the tissue to be fastened and the retainer member interlocks with the prongs of the fastener member on the other side of the tissue to hold the entire fastener structure in place. One such fastener structure and apparatus for applying it are disclosed in Green U.S. Pat. No. 4,402,445, issued Sept. 6, 1983, which is hereby incorporated by reference as background material not essential to the practice of this invention.
However, two-part fasteners of the type described in the above-incorporated patent have heretofore been unable to perform the function of uniting two edges of a wound or incision in fascia tissue and maintain the edges in sufficiently close approximation for healing to occur properly. That function has been better served by metallic staples or clips which could be applied partly on each edge of the wound or incision (hereinafter "wound") and then clinched to force the edges together and maintain the edges in close approximation.
It would be advantageous to be able to provide a fastener of resinous material, particularly absorbable resinous material, capable of joining the edges of wounds in body tissue, particularly fascia tissue, and maintaining the edges of the wound in close approximation.